RESUMO
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its emerging variants of concern (VOC), such as Delta (B.1.617.2) and Omicron (B.1.1.529), has continued to drive the worldwide pandemic. Therefore, there is a high demand for vaccines with enhanced efficacy, high thermostability, superior design flexibility, and fast manufacturing speed. Here, we report a circular RNA (circRNA) vaccine that encodes the trimeric RBD of SARS-CoV-2 Spike protein. Without the need of nucleotide modification, 5-capping or 3-polyadenylation, circRNA could be rapidly produced via in vitro transcription and is highly thermostable whether stored in naked or lipid-nanoparticle (LNP)-encapsulated format. LNP-encapsulated circRNARBD elicited potent neutralizing antibodies and T cell responses, providing robust protection against Beta (B.1.351) and native viruses in mice and rhesus macaques, respectively. Notably, circRNA vaccine enabled higher and more durable antigen production than 1m{Psi}-modified mRNA vaccine, eliciting a higher proportion of neutralizing antibodies and stronger Th1-biased immune responses. Importantly, we found that circRNARBD-Omicron vaccine induced effective neutralizing antibodies against only Omicron but not Delta variant. By contrast, circRNARBD-Delta could elicit high level of neutralizing antibodies against both Delta and Omicron. Following two doses of either native- or Delta-specific vaccination, circRNARBD-Delta, but not Omicron or Beta vaccines, could effectively boost the neutralizing antibodies against both Delta and Omicron variants. These results suggest that circRNARBD-Delta is a favorable choice for vaccination to provide a broad-spectrum protection against the current variants of concern of SARS-CoV-2.
RESUMO
The noninvasive measurement of liver stiffness (LS) was evaluated by transient elastography (FibroScan) and the possible influencing factors from the patients' clinical situations including age, gender, liver inflammation represented by alanine transaminase (ALT) and total billirubin (TBIL) level, HBV replication (HBV DNA loads), portal vein pressure (portal vessel diameter, PVD), splenic thickness (SPT) and body mass index (BMI) were analyzed in patients with chronic hepatitis B (CHB). A total of 466 patients including 31 patients with acute-on-chronic liver failure (ACLF), and 435 patients with chronic hepatitis B (CHB) among which 82 patients were diagnosed with liver cirrhosis (LC) by clinical manifestations and liver B-type ultrasonic inspection were enrolled at Tongji Hospital from April to December 2009. LS was measured by a FibroScan device (EchoSens, France). Simultaneously, ALT and TBIL levels, HBV DNA loads, PVD, SPT and BMI in all patients were also tested. Forty-one healthy volunteers served as controls. The values of LS were correlated positively with ages of CHB patients and significantly higher in males than in females. In patients with BMI>28 kg/m(2) (obesity) and abnormal levels of ALT and TBIL, LS values were significantly increased as compared with those having normal levels of ALT and TBIL. The patients with ACLF had the highest LS value. Furthermore, LS values in the patients with LC were significantly higher than those in patients without LC. It is concluded that noninvasive measurement of liver fibrosis by FibroScan provides an alternative method to evaluate liver fibrosis of patients with CHB. In order to properly illustrate the stiffness value taken by transient elastography, patients' gender should be taken into consideration and it is also suggested to avoid possible influencing factors including liver inflammation (high levels of ALT and TBIL) and obesity (high BMI).
